SCP-2XXX is to be contained in a 5m X 5m X 5m solid iron cell connected to a heat source and an electrical source both on an emergency generator in the case of a power outage following with a breach.

This is a run-on sentence, and some of the wording doesn't really make sense. I suggest, separating it into two separate parts, one detailing how it needs to be contained, and the second stating that emergency generators are to be on standby in the event of a breach. (After reading note, why these specifications? It's never explained why the cell needs to be the way it is.)

SCP-2XXX's cell must include 1 (one) twin sized bed 3 (three) layers of carpet to get rid of heat and 1 (one)…

I think writing the number out or just saying 1 is sufficient here.

SCP-2XXX must be transferred to a temporary cell bi-monthly to clean all dead D-Class personnel.

Eh, the bit about dead D-Class is a bit unnecessary. (After reading the entire article, I don't understand why there would be dead D-Class in its cell, either.) Perhaps saying something like this would work better: SCP-XXXX's containment cell is to be cleaned on a bi-monthly basis, during which time SCP-XXXX is to be transferred to a temporary holding cell.

A point I will bring up, if there are specific requirements for the cell the object is typically housed in, then will a temporary cell be sufficient to contain it or would it need to meet the same specifications as its usual chamber?

SCP-2XXX is a 2 meter tall humanoid which what appears to have no face but instead a Black head with a White Question mark on it.

Does it appear to have no face or does it have no face? This is an issue I see get brought up a lot, and rightfully so, but if an object appears to be something but isn't what it seems that needs to be explained with adequate details. If it is exactly what it looks like, using appears to be makes no sense. For more on this, check out this essay right here: What Not To Do, What To Do Instead. It has a lot of great advice in it.

Additionally, black and white shouldn't be capitalized.

SCP-2XXX looks of that of a normal human but has Super strength and Super speed. If SCP-2XXX sees what he thinks is a weapon he will then laugh while he teleports and kills that person whom he sees the weapon with. SCP-2XXX has been known to have been in over 100 murders in 5 years.

Again, no need to capitalize the word super, if it's intended to add emphasis to it, it doesn't. It just makes it seem like a grammar mistake.

As for the content of this sentence…eh. I'm afraid you've lost my interest here. This is essentially a thing that kills people, those types of articles aren't likely to go over well unless there is an absolutely sublime story to it and the writing is phenomenal, and even if they do have that, it still might not be widely regarded or liked. This is another essay you should check out: Common SCP Pitfalls, specifically, the humanoid section.

SCP-2XXX was found in the heart of ██████, Italy where a Foundation Agent while on family vacation witnessed this murder and teleportation.

This just seems highly unlikely….

Agent █████ called in Mobile Task Force ███-█ "Exorcists" to contain this anomaly. Half the team went down with weaponry and were all killed in an instant.

Another great piece of reading is this essay right here: So You Want to Write a Humanoid SCP Object, this should help you address the problem I mentioned earlier. Think about the story you're trying to tell and focus on that, you have to be able to keep the reader engaged so find a way to ensnare them into your story or make it to where they can relate to it, if applicable.

Special containment procedure 2XXX was created and then used to contain other SCPs similar to SCP-2XXX after first breach.

Hm, if the scip is extremely hostile why would the Foundation allow it near other scips? Also, first breach? I'm not sure I know what you mean by that. The first breach of the scip or the first breach that occurred while the scip was there?

Interview of Agent █████ after the instance of SCP-2XXX he witnessed.

There are other instances of this scip? I don't think that's mentioned anywhere else in this article…

Dr. ████████: You know that you killed half the team right
Agent █████: Yes. I am aware

Wait, so the agent killed the MTFs, not the scip? That isn't mentioned anywhere also, but why would they do that? I'm not following.

All in all, I honestly don't see this working out. A lot of the time, it's not about how dangerous a scip is, it's about how interesting it is. I definitely recommend you check out the essays I linked, and despite how lengthy they are, I hope you read them and find them helpful. If you're unsure about an idea, make sure you ask what other people think about it, you can do this in the Ideas and Brainstorming forum. Best of luck to you!